The structure, field-induced strain, polarization and dielectric response of lead-free SrZrO3-modified Bi-1/2(Na0.80K0.20)(1/2)TiO3 (abbreviated as BNKT-SZ100x, with x = 0-0.05) ceramics were investigated. The X-ray diffraction analysis of BNKT-SZ100x ceramics reveals no remarkable change in the crystal structure within the studied composition range. Around critical composition (x = 0.03) at a driving field of 6 kV mm(-1), large unipolar strain of 0.37% (S-max/E-max = 617) was obtained at room temperature. The ferroelectric and piezoelectric properties of BNKT ceramics were significantly increased at 2 mol%. At x = 0.02, remnant polarization reached a maximum value of 34 mu C cm(-2), while the piezoelectric constant (d(33)) attained maximum value of 190 pC/N. These results indicate that BNKT-SZ100x ceramics can be considered as promising candidate materials for lead-free piezoelectric actuator applications. (C) 2013 Elsevier B.V. All rights reserved.